1. Technical Field
The present invention relates to a film formation method, and to an orientation film formation method.
2. Related Art
In a liquid crystal display device, liquid crystals are sealed between an element substrate and an opposing substrate via a seal member. Orientation films for orienting the liquid crystals are formed on the surfaces of the element substrate and the opposing substrate that are adjacent to the liquid crystals. The orientation films are formed on substantially the entire surfaces of the element substrate and the opposing substrate, and an inkjet method is included as one method for forming the orientation films. In the inkjet method, droplets discharged on a substrate are allowed to coalesce with each other to form an orientation film pattern on the substrate. However, the droplets discharged on the substrate sometimes do not spread uniformly on the substrate. For example, the droplets contract to form stripes, droplets are attracted by other droplets to form bulges, and other problems occur, and a uniform orientation film is difficult to form.
Therefore, a film formation method has been proposed for forming a uniform thin film from droplets that are discharged by an inkjet method (for example, Japanese Laid-Open Patent Application Publication No. 2005-0721). In Japanese Laid-Open Patent Application Publication No. 2005-0721, a head having a plurality of nozzles used in an inkjet method is provided, and when the substrate is driven in the Y direction, liquid dots having a diameter of r are applied on the substrate continuously in the Y direction, and at intervals of 4r in the X direction. The liquid is applied from the head in an arrangement in which a second dot is applied adjacent to one first dot that is applied first, and then a third dot is applied adjacent to the second dot, and a fourth dot is applied adjacent to the third dot so that the fourth dot is adjacent to another first dot. At this time, a uniform film thickness in the X direction is obtained by giving the first dot a small size, the second dot an intermediate size, the third dot a large size, and the fourth dot an intermediate size. In other words, when the dots are the same size, adjacent dots are attracted to each other, and the film thickness easily becomes greater on the side in which dots are previously applied adjacent to each other than on the side in which dots are subsequently applied, and measures are taken to prevent this phenomenon.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved film formation method and orientation film formation method. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.